Constructing open many-body quantum systems with atoms, cavities and light

Trapping ultracold atoms within strongly coupled optical cavities allow us to engineer rich many-body quantum systems that are essentially open. I will describe experiments in which single, few, or many ultracold atoms are placed with high spatial control within Fabry-Perot optical cavities. Our focus generally is on pushing the limits of quantum measurement, and also exerting feedback control over quantum properties of the atomic system. I will discuss three main results: high-fidelity mid-circuit measurement within an atomic tweezer array, precise detection of an atomic ensemble undergoing non-equilibrium thermodynamics, and autonomous feedback stabilization of an atomic spin system.